Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v2] brcmfmac: fix "board_type" in brcmf_of_probe()
To:     Dan Carpenter <dan.carpenter@oracle.com>,
        Arend van Spriel <aspriel@gmail.com>,
        Matthias Brugger <mbrugger@suse.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc:     Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Chi-hsien Lin <chi-hsien.lin@infineon.com>,
        Wright Feng <wright.feng@infineon.com>,
        Chung-hsien Hsu <chung-hsien.hsu@infineon.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com,
        SHA-cyfmac-dev-list@infineon.com, kernel-janitors@vger.kernel.org
References: <YNCHELb14+eNV94n@mwanda>
From:   Hans de Goede <hdegoede@redhat.com>
Message-ID: <6e0b8291-8c61-c172-30ce-031910009d04@redhat.com>
Date:   Mon, 21 Jun 2021 14:41:03 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.10.1
MIME-Version: 1.0
In-Reply-To: <YNCHELb14+eNV94n@mwanda>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi,

On 6/21/21 2:33 PM, Dan Carpenter wrote:
> There are two bugs here:
> 1) devm_kzalloc() needs to be checked for allocation errors.
> 2) The loop was intended to be:
> 
>  Bad:	for (i = 0; i < board_type[i]; i++) {
> Good:	for (i = 0; i < len; i++) {
> 
> Neither of these bugs are likely to cause an issue in practice but
> they're worth fixing.  Also the code could be made simpler by using the
> devm_kstrdup() and strreplace() functions.
> 
> Fixes: 29e354ebeeec ("brcmfmac: Transform compatible string for FW loading")
> Suggested-by: Johannes Berg <johannes@sipsolutions.net>
> Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> v2: Basically a completely different patch.  :)
> 
>  .../net/wireless/broadcom/brcm80211/brcmfmac/of.c    | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> index a7554265f95f..8ca62cd0e8ac 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> @@ -24,20 +24,16 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>  	/* Set board-type to the first string of the machine compatible prop */
>  	root = of_find_node_by_path("/");
>  	if (root) {
> -		int i, len;
>  		char *board_type;
>  		const char *tmp;
>  
>  		of_property_read_string_index(root, "compatible", 0, &tmp);
>  
>  		/* get rid of '/' in the compatible string to be able to find the FW */
> -		len = strlen(tmp) + 1;
> -		board_type = devm_kzalloc(dev, len, GFP_KERNEL);
> -		strscpy(board_type, tmp, len);
> -		for (i = 0; i < board_type[i]; i++) {
> -			if (board_type[i] == '/')
> -				board_type[i] = '-';
> -		}
> +		board_type = devm_kstrdup(dev, tmp, GFP_KERNEL);
> +		if (!board_type)
> +			return;

The error handling here seems to be lacking, specifically
this error-exit path needs a of_node_put(root); call (or
a "goto put;" or some such)

Regards,

Hans


> +		strreplace(board_type, '/', '-');
>  		settings->board_type = board_type;
>  
>  		of_node_put(root);
>